Masts for supporting projectors

ABSTRACT

A mast for supporting light or sound projectors, which can be retracted into a position of non-use by tilting the whole device and the projectors are mounted on a ring which can slide along the mast prior to the tilting of the latter.

1 ,1 I 1 1 Ite States ate: I 1 I 1 3,827,197 Adam Aug. 6, 1974 [54] MASTS FOR SUPPORTING PROJECTORS 1,971,757 8/1934 Nerem 240/63 X 1 2 94 M I I Invenwn Marie Henri Hubert Adam, Bayou, 333222? 551%? K3525 3/1 331 France 3,292,322 12/1966 Pfaff 52/122 [73] Assignee: Societe Anonyme LEclairage 5 9 Techmque Nancy France 3:686:498 8/1972 Meyer 240/63 x [22] 1972 FOREIGN PATENTs OR APPLICATIONS pp 297,427 989,511 9/1951 France 52/40 [30] F A r f P l D t OTHER PUBLICATIONS orelgn pp Ica Ion rIorI y a a Oct. 15, 1971 France 71.37067 Uddeholm Hlgh Mast Llghtmg June 1971' 52 us. 01 52/29, 52/32, 52/40, 'f EXamiWTFYaHIF Abbmt 52/1 16, 52/122 240/64 Asszstant Exammer-Leshe A. Braun [51] Int. Cl E04h 12/18 [58] Field of Search 52/28, 29, 32, 40, 69, [57] ABSTRACT 52/83 1 122; 240/63 64; 248/221 A mast for supporting lightor sound projectors, which can be retracted into a position of non-use by tilting [56] References Cited the whole device and the projectors are mounted on a UNITED STATES PATENTS ring which can slide along the mast prior to the tilting 189,514 4/1977 Stimpson 240/63 X Of the 181ml. 465,079 12/1891 Walton 52/40 788,707 5/1905 Coverstone 240/63 4 Clalms, 9 Drawmg Flgures PAIENTEI] AUG 6I974 SHEET *0 BF 5 l MASTS FOR SUPPORTING PROJECTORS BACKGROUND OF THE INVENTION The illumination of large surfaces such asathletic fields requires the use of very high masts, on the order of some thirty meters. Such masts are naturally, not very esthetic and constitute an eyesore for adjacent owners. They also constitute a hazard to aerial navigation if they are to be situated in the takeoff cone of an airfield.

Up to the present, and when the environment made it necessary, these masts had to be retracted into the ground, but this solution, aside from its high cost, could be suitable only for fields situated on the seashore which generally had, saltwater-bearing zones at a level close to the ground. It is, of course, possible to counteract the evils of corrosion by using special alloys, but such solutions are very troublesome.

The present invention, which remedies these drawbacks, is remarkable in that this mast can pivot around a horizontal axis, from the vertical position of use to a substantially horizontal, idle position, with said mast extending beyond its axis of articulation in order to be provided with a balancing counterweight.

The set of said projectors as a whole constitutes a substantial mass which require the use of latticework beams for the embodiment of such masts. To remedy this drawback, and according to another characteristic of the invention, the projector support assembly can slide along the mast and be lowered prior to the pivoting thereof.

The present invention will be better understood from the following description, made in reference to the drawings attached by way of indicative example only, in which:

FIG. 1 is an elevation of a mast according to the invention,

FIG. 2 is the left hand view of FIG. 1,

FIG. 3 is a view analogous to FIG. 1, showing a modification,

FIG. 4 is the lef-hand view of FIG. 3,

FIG. 5 is an enlarged partial view in perspective showing, in the case of FIGS. 3 and 4, the guide means of the whole mobile projector support assembly, with said assembly (not shown) being assumed to be in its lower position,

FIG. 6 is a partial front view of the device in FIG. 5,

FIG. 7 is a view in section taken along the line VII- VII in FIG. 6,

FIG. 8 is an exploded view in perspective of the upper end of the mast in FIGS. 3 and 4, and,

FIG. 9 is a view on a larger scale and in section taken along line IX-IX in FIG. 6.

Referring to FIGS. 1 and 2, the projectors l are fixed on a support 2 situated at the upper end of a lattice beam 3 constituting the mast proper. According to the present invention, the mast 3 has, in proximity to its lower end, an axis of articulation 4 which can pivot in the bearings 5 on a pedestal 6. The lower end of mast 3, extending beyond axis 4, is provided with a counterweight 7 for balance. The mass of the counter-weight is constituted, for example, by dry sand.

The pedestal 6 is provided with a stop 8 for positioning the mast vertically. Means, not shown, are also provided to lock the mast in this vertical position with stop 8 possibly being used advantageously for this purpose.

The mast is pivoted with the aid of a motor-reducer set, not shown, keyed, for example, at the end of axis 4.

The pedestal 6 is anchored in a block of concrete supporting the whole apparatus.

Mast 3 must be constituted by a very rigid beam because the weight of assembly 1 2 is on the order of 600 kilograms and more.

Since this beam 3 produces a very doubtful esthetic effect, the projector support should be lowered before pivoting, in order to be able to use a finer mast. This is the solution which will be described in reference to FIGS. 3 to 9.

Projectors 1 are supported by a ring 9, normally situated on the upper part of a tubular mast 10 and capable of being displaced along said mast in order to be brought in proximity to the control platform 11 situated on the upper part of a pedestal 12. As before, mast 10 has an axis 13 which can pivot in two horizontal bearings 14 fixedly mounted on platform 11. A motorreducer set 15 connected to one end of axis 13, insures the pivoting of the mast.

The displacement of ring 9 is insured by a cable 16, winding, at the level of the platform, on the drum of a winch 17 and then passing inside the mast to the top of the mast where it winds over a pulley 18 and extends outward along said mast and is fixed to the ring 9. Conventional means are provided for locking the ring on the upper part of the mast.

The ring 9 is fixedly connected to a carriage 19 guided on a rail 20 extending along the mast 10. Carriage 19 has a U-shaped cross section, with the lateral arms extending perpendicularly to the edges 21 of rail 20 and the guidance thereof being insured on the one hand by rollers 22 and 23 disposed on either side of the wings 24 of said rail, and on the other hand by centering rails 25 disposed according to FIG. 9.

Carriage 19 is provided with a brake device as follows:

Said cable 16 is fixed on the median part of a cap 26 which can pivot on a shaft 27, the ends of which are fixedly connected to carriage 19. The vanes of cap 26 are linked in rotation, by means of a locking finger 28, to cams 29 which can pivot on shaft 27, and which extend through an opening 30 made in the median part of the carriage 19. Springs 31 each fixed by one end to carriage l9 and by the other end to the median part of cap 26, tend to pivot the cams 29 and apply them against the rail 20 (FIG. 7).

If cable 16 breaks, springs 31 expand and immediately, by means of the cap, apply the cams 29 against rail 20 with said cams producing the braking effect by self-clamping. This braking device also offers the advantage of immobilizing the ring 9 with respect to the mast as soon as cable 16 is relaxed and this permits lowering the mast below the horizontal.

Line 33 feeding the projectors is constituted by a flexible cable fixed at intervals on small carriages 34 which are free in translation. Rail 29 is advantageously used to insure guidance of said carriages 34 (FIG. 5).

Finally, the mast is equipped with a limit switch 35 whose trip is influenced by two cams 36 situated at the top and at the bottom of the mast, as shown in FIG. 5.

What I claim is:

l. A mast for supporting projectors comprising a mast pivotally mounted near its base on a horizontal axis, a guide rail extending along said mast, a carriage moveably mounted on said rail, a ring supporting the projectors and connected to said carriage, a cable connected to said ring, a pulley mounted on the top of said mast and having said cable extending thereover, a shaft extending through said carriage, a cap rotatably mounted on said shaft and connected to said cable, cams rotatably mounted on said shaft, said carriage having an opening with said cam extending therethrough for at times engaging said rail, means connecting said cap and said cams and resilient means tending to pivot said cams against said rail and means for pulling said cable for moving said cams from said rail.

2. A mast for supporting projectors as claimed in claim 1 wherein an electric cable is connected to said projectors, extends exteriorily of said mast and further carriages are slideably mounted on said rail and have succeeding portions of said electric cable connected thereto.

3. A mast for supporting projectors comprising a mast, a guide rail extending along said mast, a carriage slideably mounted on said rail, a ring supporting the projectors, a cable, a pulley mounted on said mast and having said cable extending thereover, a shaft on said carriage, a cap pivotally mounted on said shaft and connected to said cable, cams rotatably mounted on said shaft, said carriage having an opening with said cams extending therethrough towards said rail, springs connected to said cap and said mast tending to pivot said cap moving said cams against said rail and pulling said cable.

4. A mast for supporting projectors as claimed in claim 3 wherein an electric cable is connected to said projectors, extends exteriorly of said mast and further carriages are slideably mounted on said rail and having succeeding portions of said electric cable connected thereto. 

1. A mast for supporting projectors comprising a mast pivotally mounted near its base on a horizontal axis, a guide rail extending along said mast, a carriage moveably mounted on said rail, a ring supporting the projectors and connected to said carriage, a cable connected to said ring, a pulley mounted on the top of said mast and having said cable extending thereover, a shaft extending through said carriage, a cap rotatably mounted on said shaft and connected to said cabLe, cams rotatably mounted on said shaft, said carriage having an opening with said cam extending therethrough for at times engaging said rail, means connecting said cap and said cams and resilient means tending to pivot said cams against said rail and means for pulling said cable for moving said cams from said rail.
 2. A mast for supporting projectors as claimed in claim 1 wherein an electric cable is connected to said projectors, extends exteriorily of said mast and further carriages are slideably mounted on said rail and have succeeding portions of said electric cable connected thereto.
 3. A mast for supporting projectors comprising a mast, a guide rail extending along said mast, a carriage slideably mounted on said rail, a ring supporting the projectors, a cable, a pulley mounted on said mast and having said cable extending thereover, a shaft on said carriage, a cap pivotally mounted on said shaft and connected to said cable, cams rotatably mounted on said shaft, said carriage having an opening with said cams extending therethrough towards said rail, springs connected to said cap and said mast tending to pivot said cap moving said cams against said rail and pulling said cable.
 4. A mast for supporting projectors as claimed in claim 3 wherein an electric cable is connected to said projectors, extends exteriorly of said mast and further carriages are slideably mounted on said rail and having succeeding portions of said electric cable connected thereto. 